Automatic driver-brake retainer.



No. 675,864. Patented lune 4, I90l. W. T. SIMPSON.

AUTOMATIC DRIVER BRAKE RETAINER.

(Application filed my 3, 1900.)

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No. 675,864. Patented June 4, I90l. W. T. SIMPSON.

AUTOMATIC DRIVER BRAKE RETAINER.

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UNITED STATES PATENT OFFICE.

\VILLIAM T. SIMPSON, OF BATTLECREEK, MICHIGAN, ASSIGNOR TO THE MICHIGAN LUBRICATOR CO., OF DETROIT, MICHIGAN.

AUTOMATIC DRIVER-BRAKE RETAINER.

SPECIFICATION forming part of Letters Patent No. 675,864, dated June 4, 1901. Application filed May 3,1900. Serial No. 15,319. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM T. SIMPSON, a citizen of the United States, residing at Battleereek, in the county of Calhoun, State of Michigan, have invented certain new and useful Improvements in Automatic Driver- Brake Retainers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being, had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

This invention relates to an automatic driver-brake retainer designed for use in connection with an air-brake system; and it consists in the construction and arrangement of parts hereinafter fully set forth, and pointed out particularly in the claims.

The object of the invention is to provide simple and efficient means for retaining a certain predetermined pressure in the driverbrake cylinder when the lever of the engineers brake-valve is moved to the full-release position, whereby all brakes are released excepting the driver-brake, which may be held applied with sufficient force to keep the train bunched and prevent the train from pulling apart through an accelerated movement of the engine upon the release of the brakes.

The above object is attained by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a diagrammatical view, partly in section, showing an engineers brake-valve with my improved retainer attached thereto, a triple valve common in air-brake systems, the auxiliary reservoir, the driver-brake cylinder, and suitable pipes connecting said parts. Fig. 2 is a plan view of an engiueers brake-valve with my improved retaining device mounted thereon. Fig. 3 is a view of a portion of the engineers brake-valve in elevation and a longitudinal sectional view through my retaining device connected therewith. Fig. 4 is a transverse section, as on line 4. 4 of Fig. 3. Fig. 5 is an end elevation of the retaining device, showing the bifurcated lever for actuating the plug-cock valve in the exhaust-pipe of the brake-cylinder and by dotted lines the various movements of said lever.

In the ordinary use of air-brakes upon long trains it has been found dangerous to release the brakes with the train running at a considerable speed, owing to the fact that upon the releasing of the brakes the engine and forward end of the train will run away from the rear end thereof, because of the greater impetus of the engine and tender when in motion and the further fact that the brakes upon the rear of a train are not released as quickly as those forward. It therefore often occurs that the slack in the couplings will allow the forward end of the train to obtain an accelerated motion before the rear end is fairly under way, resulting in a parting of the train by the pulling out of the draw-bar and sometimes derailing the cars. By means of my automatic driver-brake retainer a certain pressure is retained in the driver-brake cylinder when the brake-cylinders in the balance of the train have been released, preventing the engine from surging ahead and keeping the train bunched untilperfectly under control, thereby obviating the liability of the parting of the train and avoiding the damage and delay incident thereto.

Referring to the characters of reference, 1 designates the engineers brake-valve, which is connected with the main reservoir (not shown) by the pipe 2. Also connected with said brake-valve is the brake or train pipe 3, which extends the full length of the train. The train-pipe communicates with the triple valve 4:, which in turn is connected with the auxiliary reservoir 5 through pipe 6 and the brakecylinder 7 through pipe 8. The brakevalve, triple valve, auxiliary reservoir, brakecylinder, and connecting-pipes are common to the Westinghouse air-brake system, and as their construction forms no part of this invention a detail description thereof will not be necessary. A general description of the operation of an air-brake system will be necessary, however, to illustrate the application of my invention.

\Vith the handle 9 of the brake-valve in the running position, which is the first dotted position to the right shown in Fig. 2, air under pressure from the main reservoir flows through said valve into the train-pipe 3,thence through the port 10 into chamber 11 of the triple valve, through a bypass 12, around the piston 13 of said valve into chamber ll, and thence through pipe 0 into the auxiliaryreservoir 5, charging said reservoir with trainpipe pressure. \Vith the handle of the engineers brake-valve in the running position the pressure in chambers 11 and 14 is equalized, maintaining the piston 13 in the position shown in Fig. 1. Vhen it is desired to apply the brakes, the handle 9 of the brakevalve is moved to the position of application, which is the second dotted position shown in Fig. 2. This movement of the brake-valve closes the port between the train-pipe and the main reservoir and red uces the pressure above the piston 15 in said brake-valve, causing the excess of pressure in the train-pipe to raise the piston and open the exhaustport 16, permitting the air in the train-pipe to escape to atmosphere. This release of the air in the train-pipe reduces the pressure in chamber 11 below the piston 13 of the triple valve, when the excess of pressure in the auxiliary reservoir 5 will force said piston downward and carry with it the slide-valve 17, which is attached thereto, thereby opening the port 18 and permitting the air in the auxiliary reservoir to flow into the brake-cylinder through the connecting-pipe 8, thereby moving the piston 19 of the cylinder and applying the brakes through the medium of the brake-lever (not shown) which is attached to the piston-rod 20 of said brake-cylinder. To release the brakes, the handle of the brake valve is returned to the position shown by solid lines in Fig. 2, thereby operating the brake-valve 21 to again establish communication between the main reservoir and the train-pipe, when the excess of pressure from the main reservoir in chamber 11 of the triple valve will raise the piston 13 and move the slide-valve 17, so as to close the portlS from communication with the auxiliary reservoir and at the same time place said port through a channel 22 in said valve in communication with the exhaust-port 23, permitting the air from the ln'ake-cylinder to pass out through said ports and into the exhaust-pipe 24, whose discharge end in ordinary practice isopen to the atmosphere, so that all 01": theair in the brake-cylinder may escape therefrom. In the application of my invention I place in the discharge end 25 of the exhaust-pipe 24 a plugcock valve 26, adapted to control said disehargeopening. Mounted on the stem of said valve 26 is a bifurcated lever 28, in the fork of which the free end of a tripping-bar 29 is adapted to lie, the opposite end of said tripping-bar being mounted on the end of the stem of the brake-valve and adapted to move in unison with the movement of the brakevalve handle 9. The position of said parts is such that when the brake-valve handle 9 is moved to the running position the tripping bar 29 will be swung to actuate the forked lever 28 and rotate the valve 26 to cause its port 27 to register with the discharge-opening 25 in the end of the exhaust-pipe, in which position said plug-cock remains while the handle of the brake-valve is in the running position and when said handle is moved to the position to effect an application of the brakes. Upon returning the handle of the brake-valve to the full-release position, however, the tripping-bar 29 engages the forked lever of said plug-cock valve and actuates it to close the discharge-opening of the exhaustpipe 24, which communicates with the triple valve and with the driver-brake cylinder only, so that the bringing of the brake-valve lever to the full-release position effects a release of all the brakes of the train excepting the driver-brake. This closing of the discharge-opening of the exhaust-pipe from the driver-brake cylinder causes the air which has been released from the cylinder and fills the exhaustpipe ill to raise the weighted valve 30, seated in a valve-case 31 and communicating with said exhaust pipe. The raising of the valve 530 permits the air to fill the chamber of said valve and escape therefrom to the atmosphere through the small discharge-port 32 (see Fig. 4) until the pressure in the driver-brake cylinder has been overcome by the gravity of the weighted valve 30, when said valve will drop to its seat 33 and prevent any further escape of air from the l.)rake-cylinder, thereby retaining within said cylinder a sullieient pressure to maintain the d river-brakes forcibly in application. The degree of pressure which is retained in the brake-cylinder may be regulated by the weight of the valve 30, enabling such pressure to be retained in said cylinder as may be required. The retained pressure in the driverbrake cylinder holds the engine in check, keeps the cars bunched, and prevents the surging of the train, so that upon the release of the brakes the forward end of the train is prevented from running away from the rear end and a parting of the train avoided. If it is not desired to come to a full stop, the handle of the brake-valve is retained in the full-release position until all of the brakes of the train have been fully released and the train under control, when by moving the handle of the brake-valve to the running position the tripping-bar will be actuated to open the plug-cock valve 26 and permit the escape of the retained air in the driver-brake cylinder.

An additional advantage of the (1 riverbrake retainer is that when coming to a full stop at a water-tank, on a siding, or at any point where it is desired to make a stop the throwing ot' the brake-valve handle to the full-release position retains a minimum pressure in the driver-brake cylinder and holds the driver-ln'ake applied with suflicient force to prevent any accidental starting of the train through a possible leakage of steam, a slight grade in the track, or other cause, the retained pressure being instantly released when the brake-valve handle is moved to the running position before the starting of the train.

Should it be desired to dispense with the operation of the automatic retainer, the bifurcated lever 28 of the plug-cock valve may be thrown to the dotted position shown on the right of Fig. 5, when the discharge end of pipe 2t will open to the atmosphere and the lever of the plug-cock valve 26 will stand out of the path of the tripping-bar 29, so that an operation of the handle of the brake-valve will not operate said plug-cock.

It will be seen by referring to Fig. 5 that one side of the forked lever 28 is longer than the other, whereby the swinging of the brakevalve handle to the right will cause the closing of the plug-cock and at the same time carry the short side of the fork into position to be engaged by the tripping-bar when the brake-valve handle is returned to the full-release position, thereby actuating said plugcock to close the discharge-opening of the exhaust-pipe 24.

It will be seen that the operation of the d river-brake retainer is purely automatic and simultaneous with the movement of the brakevalve handle to the release position, so that no especial care need be exercised by the engineer, as the operation of the device is positive and concurrent with the movement of the brake-valve handle, requiring no separate or independent movement of any other part, assuring the engineer that the throwing of the brake-valve handle to the release position will cause the retention of a certain pressure in the driver-brake cylinder.

Having thus fully set forth my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a brake-retainer, the combination with an air-brake system involving a brakecylinder and a brake-valve for controlling the passage of air to and from said cylinder said brake-valve having an operative handle, of a retaining-valve adapted to control the passage of air from the exhaust-pipe of said cylinder and means connected with and operated through a movement of the brake-valve handle to close said retaining-valve and retain a minimum pressure of air Within the brake-cylinder.

2. In an airbrake retainer,the combination with an air-brake system including a brakecylinder and a brake-valve having an operative handle for controlling the passage of air to and from said cylinder, of means actuated in conjunction with the brake-valve handle for discharging the maximum pressure from the brake-cylinder and retaining a minimum pressure therein.

3. In an air-brake retainer, the combination with an air-brake system containing a brakecylinder and a brake-valve, of a pressure-retaining device adapted to retain a certain pressure in the brake-cylinder upon the release of the maximum pressure therein, said retaining device being connected with the brake-valve and automatically actuated when the brake-valve is removed to the position of release.

4-. In an air-brake retainer, the combination with an air-brake system including a brakecylinder, a brake-valve for controlling the passage of air to and from said cylinder, of an exhaust-pipe communicating with the brakecylinder, a valve for closing the discharge end of said exhaust-pipe, a gravity-valve also conimunicating with said exhaust pipe and means connecting the valve controlling the discharge-port of said pipe with the handle of the brake-valve.

5. In an air-brake retainer, the combination with an air-brake system including a brakecylinder and a brake-valve for controlling the passage of air to and from said cylinder, of a pressure-retaining device located in the discharge-pipe of the brake-cylinder and means connecting said retaining device with the handle of the brake-valve, whereby a certain pressure is retained in the brake-cylinder when the handle of the brake-valve is moved to the position of release.

6. In an air-brake retainer, the combination with an air-brake system including a brakecylinder, at brake-valve having an operative handle said valve controlling the passage of air to said cylinder and the release of air there from and means connected with the brakcvalve handle for automatically retaining a certain pressure within the brake-cylinder upon the inovementof the brakevalve handle to the position of release.

7. In an air-brake retainer, the combination with an air-brake system, including a brakccylinder and a brake-valve, of means connected with the brake-valve for automatically retaining a certain pressure in the brake-cylinder upon the movement of the brake-valve to the position of release and means also connected with the brake-valve for releasing the contained pressure in the brake-oylinder upon the movement of the brakc valve to the running position.

8. In an airbrake retainer, the combination with an air-brake system containing a brake cylinder and a brake-valve, of means for re taining a certain pressure in the brake-cyliir der and discharging said retained pressure therefrom, said means being connected with and automatically actuated by the movement of the brake-valve.

In testimony whereof I sign this specifica tion in the presence of two witnesses.

\VILLIAM T. SIMPSON.

Witnesses:

E. S. WHEELER, 0. EDNA JosLIN.

ITO 

